During this fiscal year, this project, originally begun when Dr. Bailey-Wilson was a Professor at Louisiana State University Medical Center, has been continued. Work accomplished in this fiscal year has included screening of cases and collection of family data, blood and tissue samples. The purpose of this study is to identify a gene or genes that contribute to lung cancer susceptibility. The specific aims are to 1) collect family history and environmental risk factor data about lung cancer from lung cancer patients and their families and to also collect blood and tissue samples from a subset of the families that appear informative for linkage analysis; 2) genotype the biological samples for a genome wide set of marker loci; 3) perform a genome-wide linkage analysis to attempt to localize a lung cancer susceptibility locus (loci). In this fiscal year, family history and biologic samples have been collected from both new and previously studied families. Data collection is ongoing and expected to continue for several more years. Dr. Bailey-Wilson has been instrumental in founding the Genetic Epidemiology of Lung Cancer Consortium (GELCC) for the purpose of obtaining additional family data from a large group of collaborative investigators. Previous analysis of candidate regions in five GELCC families, including two of Dr. Bailey-Wilson's families gave some evidence of linkage in one of these regions. However, the extremely small sample size requires that conclusions be postponed until more data are available. Two additional sets of families were genotyped for approximately 400 markers at the Center for Inherited Disease Research (CIDR) during this fiscal year and the previous fiscal year. Approximately one-fifth of this set of families are from the Louisiana data collection effort. Data checking has been performed on these data and many errors have been resolved. Genotype data from the genome wide screen of the larger number of families has been analyzed this year and analyses will be ongoing in the next fiscal year. Several candidate regions have been suggested by these analyses and additional genotyping is ongoing in Dr. Anderson's lab to follow-up on these results. As head of the GELCC Analysis committee, Dr. Bailey-Wilson is in charge of the analyses of these data.